Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be multiple-access systems capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include code-division multiple access (CDMA) systems, time-division multiple access (TDMA) systems, frequency-division multiple access (FDMA) systems, and orthogonal frequency-division multiple access (OFDMA) systems.
In some wireless communication systems, multiple radio access technologies (RATs) may be simultaneously used by a single or multiple different devices—for example, a user equipment (UE) may have a wireless local area network (WLAN) connection with a Wi-Fi router and simultaneously have a wireless wide area network (WWAN) connection with an LTE eNodeB. Or, a first UE may have a WLAN connection with a Wi-Fi router while a second, nearby UE has an WWAN connection with an LTE eNodeB. In either scenario, and generally speaking, transmissions on one RAT may interfere with transmissions on another RAT due to, for example, third order harmonics arising from non-linear components in the transmission chain of the “aggressor” signal, adjacent channel interference leakage, intermodulation interference, and so forth. This interference can distort the received signals and lead to degradation in the wireless communication. One method for reducing the distortion is to use a non-linear interference cancelation (NLIC) filter, by which the distortion caused by the aggressor signal is estimated and then removed from the victim received signal.
Many devices today include multiple receive antennas for any given type of RAT, including for use in multiple-input-multiple-output (MIMO) applications. The distortion seen at each of the multiple receive antennas may, however, be different in both phase and magnitude than the distortion seen at the other receive antennas due to the different physical location of each receive antenna, and thus the different propagation paths and times from a common transmitter. Conventionally, a separate NLIC filter is used for each receive antenna in order to separately remove the distortion at each of the receive antennas.